气候变化领域集成服务门户(CCPortal): Submarine Landslide Kinematics Derived From High-Resolution Imaging in Port Valdez, Alaska

CCPortal

DOI	10.1029/2019JB018007
	Submarine Landslide Kinematics Derived From High-Resolution Imaging in Port Valdez, Alaska
	Roland E.; Haeussler P.; Parsons T.; Hart P.
发表日期	2020
ISSN	21699313
卷号	125 期号:7
英文摘要	Submarine landslides caused by strong ground shaking during the M9.2 1964 Great Alaska earthquake generated a tsunami that destroyed much of the old town of Valdez, Alaska, and was responsible for 32 deaths at that location. We explore structural details of the 1964 landslide deposit, as well as landslide deposits from earlier events, in order to characterize kinematics of the landslide process. We present a new high-resolution seismic reflection data set that images the 1964 landslide deposit and six pre-1964 deposits with great detail. These deposits are represented by thick packages (~7–23 m) of debris within >500 m of fjord sedimentation above basement. Internal slide structures are associated with distinctive landslide failure mechanisms, including detailed erosional and depositional features and structures resolved within both landslide blocks and distal debris flow layers. Based on comparisons of deposit volume from subbottom structure and differenced bathymetry, we refine prior interpretations of the source of failed material. New data show evidence for basal erosion and reworking of fjord-floor sedimentation. Additionally, material comprising the 1964 landslide appears to have been translated and deformed by lateral thrusting, rather than having been sourced entirely from upslope evacuation zones. Taking into account these complexities in depositional patterns, we show variations in slide size through Holocene time and relate the history of landslides to the paleoseismic record. Collectively, these new observations demonstrate that Port Valdez has a repeated history of large submarine landslides, which are likely associated with large megathrust earthquakes. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	landslide mechanism; paleoseismic; seismic reflection; submarine landslide; tsunami
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187741
作者单位	School of Oceanography, University of Washington, Seattle, WA, United States; U.S. Geological Survey, Anchorage, AK, United States; U.S. Geological Survey, Menlo Park, CA, United States
推荐引用方式 GB/T 7714	Roland E.,Haeussler P.,Parsons T.,et al. Submarine Landslide Kinematics Derived From High-Resolution Imaging in Port Valdez, Alaska[J],2020,125(7).
APA	Roland E.,Haeussler P.,Parsons T.,&Hart P..(2020).Submarine Landslide Kinematics Derived From High-Resolution Imaging in Port Valdez, Alaska.Journal of Geophysical Research: Solid Earth,125(7).
MLA	Roland E.,et al."Submarine Landslide Kinematics Derived From High-Resolution Imaging in Port Valdez, Alaska".Journal of Geophysical Research: Solid Earth 125.7(2020).